Clarkia borealis
Encyclopedia
Clarkia borealis is a rare species of flowering plant in the evening primrose family
known by the common name northern clarkia. It is endemic to California
, where it is known from the forests of the southern Klamath Range and the southernmost Cascade Range foothills
. It is an annual herb growing an erect, slender stem. The leaves are oval in shape and borne on short petioles
. The top of the stem is occupied by the inflorescence
, in which the lowest flowers open first and hanging, pointed flower buds occur at nodes at the top. The sepal
s separate as the flower blooms, revealing purplish pink petals. Each petal is between 1 and two centimeters long, elongated triangular to semicircular in shape, and sometimes flecked with dark purple. There are 8 stamen
s with anthers bearing blue-gray pollen
, and a protruding stigma
.
Both subspecies of this plant are rare. ssp. biloba is known from only about 20 occurrences in Shasta
and Trinity Counties
, and the even less common ssp. arida, the Shasta clarkia, is known only from the forests around Shingletown
.
Onagraceae
Onagraceae, also known as the Willowherb family or Evening Primrose family, are a family of flowering plants. The family includes about 640-650 species of herbs, shrubs, and trees in 20-24 genera...
known by the common name northern clarkia. It is endemic to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, where it is known from the forests of the southern Klamath Range and the southernmost Cascade Range foothills
Cascade Range
The Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...
. It is an annual herb growing an erect, slender stem. The leaves are oval in shape and borne on short petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. The top of the stem is occupied by the inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
, in which the lowest flowers open first and hanging, pointed flower buds occur at nodes at the top. The sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s separate as the flower blooms, revealing purplish pink petals. Each petal is between 1 and two centimeters long, elongated triangular to semicircular in shape, and sometimes flecked with dark purple. There are 8 stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s with anthers bearing blue-gray pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
, and a protruding stigma
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
.
Both subspecies of this plant are rare. ssp. biloba is known from only about 20 occurrences in Shasta
Shasta County, California
Shasta County is a county located in the northern portion of the U.S. state of California. The county occupies the northern reaches of the Sacramento Valley, with portions extending into the southern reaches of the Cascade Range. As of the 2010 census, the population was 177,223, up from 163,256...
and Trinity Counties
Trinity County, California
Trinity County is a large, rugged and mountainous, heavily forested county located in the northwestern portion of the U.S. state of California, along the Trinity River and within the Salmon/Klamath Mountains. It covers an area of over two million acres , and as of the 2010 census its population...
, and the even less common ssp. arida, the Shasta clarkia, is known only from the forests around Shingletown
Shingletown, California
Shingletown is a census-designated place in Shasta County, California, United States. The population was 2,283 at the 2010 census, up from 2,222 at the 2000 census....
.